viafb: fix ioremap_nocache error handling

Correct the returned error code for remapping the video framebuffer.
Introduce error handling for remapping MMIO register address space to
avoid a NULL pointer dereference.  Disable hardware acceleration if
remapping MMIO register address space failed as those registers are only
used for hardware acceleration.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Scott Fang <ScottFang@viatech.com.cn>
Cc: Joseph Chan <JosephChan@via.com.tw>
Cc: Harald Welte <laforge@gnumonks.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/video/via/viafbdev.c b/drivers/video/via/viafbdev.c
index 743eed48a5f7..72759b620e7f 100644
--- a/drivers/video/via/viafbdev.c
+++ b/drivers/video/via/viafbdev.c
@@ -2134,12 +2134,16 @@ static int __devinit via_pci_probe(void)
 
         if (!viaparinfo->fbmem_virt) {
                 printk(KERN_INFO "ioremap failed\n");
-                return -1;
+                return -ENOMEM;
         }
 
         viafb_get_mmio_info(&viaparinfo->mmio_base, &viaparinfo->mmio_len);
         viaparinfo->io_virt = ioremap_nocache(viaparinfo->mmio_base,
                 viaparinfo->mmio_len);
+        if (!viaparinfo->io_virt) {
+                printk(KERN_WARNING "ioremap failed: hardware acceleration disabled\n");
+                viafb_accel = 0;
+        }
 
         viafbinfo->node = 0;
         viafbinfo->fbops = &viafb_ops;